The present invention relates to frame building truss arrangements and construction processes utilizing wooden foundation walls.
Typical frame building construction involves a well worn procedure of excavating, pouring a concrete footing, "forming-up" for pouring a foundation wall, pouring the wall, waiting for the concrete in the wall to cure, removing the forms, setting a sill plate, and installing the floor joist on the sills. This is all done before the wall and roof framing can be done. The tedious procedure of laying a foundation wall is expensive due to the ever increasing costs of concrete, and labor costs in constructing and dismantling the forms. Material is often wasted in the form materials, which must eventually be discarded. Precious time is lost not only in the forming up process but in the curing time required before construction can continue. Thus, it can be understood that a significant part of the expense in framing construction goes for the foundation wall.
This expense has remained even though the Federal Housing Administration has approved treated wood as foundation wall material. Although the treated wood materials, including treated foundation wall studs and plywood sheathing, may be less costly than concrete, labor has more than made up the savings. Time involved in cutting the studs, nailing a plate across the tops, securing floor joist for support, and attaching the treated plywood sheathing often raises the overall costs above similar costs for concrete foundation. Contractors have therefore been reluctant to construct with wooden foundations.
It is clearly evident that there is a severe need for affordable housing, especially in the present times when the inflation rate seems to be outrun only by elevating mortgage loan interest rates. Builders have therefore been eagerly seeking new and less expensive building systems so a broader range of purchasers can be accommodated. Studies have been completed wherein every expense down to the number of nails used is justified in order to reduce building costs. Some savings have been produced but not significant enough to broaden the range of potential buyers.
Some success has been achieved by "pre-fab" builders who save costs by mass producing homes at a single location, then shipping the finished product to a building site. This approach has only limited success, depending upon the distance to the home site, dangers of transportation, and design limitation due to transport size requirements. Still, though, the standard concrete foundation wall structure is typically used. Also, the concrete must be allowed to cure before the prefab home is lowered into place. Alternately, the foundation wall is formed of treated wood, using the same system briefly described above. "Prefab" is therefore not a universal answer to the affordable housing dilemma.
Other forms of housing do not require any form of permanent foundation. "Mobile homes" are typically supported entirely above the ground with framing that is substantially self supporting. Heavy foundation walls are therefore unnecessary. Nevertheless, certain undercarriage structurs have been developed that can be installed between a mobile home and the ground surface in order to provide stable, more permanent support. One such arrangement is illustrated in U.S. Pat. No. 4,261,149 which discloses a mobile home support comprised of horizontal metal I-beam and upright adjustable support posts. Diagonal braces are provided for stability intermediate the posts and to brace the supports. The intent of this support system is to provide level support to a structure already provided with self supporting framing. The system appears to be serviceable for its intended use with mobile homes. It is pointed out however, that the metal structure cannot be used as typical underground foundation framing due to the peculiar construction adapted especially for mobile homes. Building code requirements will not allow the use of metal as an underground foundation.
"Modular" building systems have been proposed as a more affordable form of construction. Many such units are presently on the market, ranging from "kits" wherein precut lumber is supplied along with necessary building components, to prebuilt modules such as complete wall units that can be quickly fitted together on a previously prepared foundation. Provisions for a concrete foundation are supplied along with the modular building system disclosed in U.S. Pat. No. 4,033,081 to Perkins. Concrete filled metal pedestals are used for support; a complete departure from well known framing techniques.
The present invention involves a framing construction system that allows standard frame structures of housing to be produced efficiently, using universally available materials and that does not require special training or expertise of the framing carpenter. The present invention involves the use of a truss that is comprised of a combination of a floor joist and foundation wall stud. When the trusses are attached to a footing sill plate, the floor trusses and foundation stud wall are erected simultaneously. This substantially reduces the time involved in framing the foundation wall and floor joist and lowers cost of materials used.
It is therefore a primary object of the present invention to provide a building system that can be used effectively and efficiently to substantially reduce the overall cost of framed construction.
Another object is to provide such a system that is versatile, allowing for wide discretion and style of construction.
Another object is to provide such a system that will produce a significant affect on construction completion dates in addition to savings in materials and labor cost, thereby favorably affecting cash flow situations and reducing borrowing requirements.
A still further object is to provide such a system that incorporates relatively standard carpentry practices well familiar to experienced framing contractors and therefore can be easily learned and used.
A still further object is to provide such a system that makes use of widely available materials that can be easily provided by standard truss manufacturers without requiring substantial retooling.
These and still further objects and advantages will become apparent upon reading the following description and in view of the attached drawings.